Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations cover the safety profile (readOnly, idempotent, non-destructive, closed-world), and the description adds genuinely new behavioral facts: the routing is deterministic, no LLM is involved, the response includes the tool's data plus resort, citation URLs and a dated quotable sentence, and unanswerable questions return `answerable: false` with suggestions rather than a guess. The failure mode disclosure is exactly the kind of context an agent cannot get from structured fields.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Front-loaded with the core contract in the first clause, then progressively adds routing detail, return shape, and failure behavior. Dense but every sentence carries information; the long parenthetical intent list is the only slightly heavy element.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Although an output schema exists (so return values need not be described), the description still sketches the response shape and the `answerable: false` path, and it covers the deterministic, no-LLM guarantee. Nothing an agent needs to decide whether and how to call this router is missing.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100% and the single `question` parameter is well documented with examples and a 300-char limit, so baseline is 3. The description goes further by explaining how the question string is interpreted — resort resolved by name or nickname, intent inferred from wording — which is meaningful semantics the schema cannot express.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb+resource with unusual precision: 'One natural-language question in, one tool result out,' and immediately explains the routing mechanism (resolve resort, pick intent, call matching tool). This clearly distinguishes it from the sibling tools, which each handle a single fixed intent.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The enumerated intent list (snow, open/closed, forecast, cams, history, compare, where did it snow, percent of normal, profile, regions, alerts) tells an agent exactly which classes of question belong here and maps them to the sibling tools it will dispatch to. It stops short of explicitly stating when to call this router instead of invoking a specific sibling directly, which is the one remaining routing decision.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.